An operational amplifier (often referred to as an op-amp) is a DC-coupled high-gain electronic voltage amplifier with a differential input and, usually, a single-ended output. In this configuration, an op-amp produces an output potential (relative to circuit ground) that is typically hundreds of thousands of times larger than the potential difference between input terminals of the op-amp. By applying negative feedback on an op-amp, the operational characteristics of the op-amp circuit, including the op-amp's gain, input and output impedance, bandwidth are determined by external components and have little dependence on temperature coefficients or manufacturing variations in the op-amp itself. Op-amps are among the most widely used electronic devices, and op-amps are employed in an array of consumer, industrial, and scientific devices. Op-amps can be packaged as components. Alternatively, op-amps can be employed as elements of more complex integrated circuits.
Op-amps are often trimmed during or after manufacture to improve the precision and accuracy of the devices. Some of the main objectives for trimming techniques include the correction of parameters of the op-amp, such as offset, gain, temperature drift and the like. To perform trimming, test circuitry is often used to measure the device parameters to make a determination as to how many and which of the specific memory cells in an op-amp should be programmed.